Acetonaemia is a metabolic disease that affects both cows and ewes, though it goes by different names depending on the species. In cows, it’s usually called ketosis. In ewes, it’s known as sleepy sickness, pregnancy toxaemia or twin lamb disease. Whatever the name, it’s a serious condition that can lead to death if not managed properly.

Ketosis in Cows

Ketosis is most common in high-producing dairy cows during early lactation. It typically affects the best-performing animals, where the energy demand for milk production exceeds the energy provided by feed. In simple terms, the cow is burning more energy than she’s eating.

Signs of Ketosis in Cows

• Dullness or depression

• Reduced appetite

• Drop in milk production

• Weight loss

• Staggering or aimless wandering

• Twitching of the face and ears

• Blindness

• Recumbency and coma

• Death within a few days if untreated

Sometimes the only signs are a lower milk yield and gradual loss of condition, which makes early detection more difficult.

Sleepy Sickness in Ewes

In sheep, this condition is commonly called sleepy sickness, pregnancy toxaemia or twin lamb disease. It is the most frequent metabolic disorder in ewes and usually occurs in the final weeks of pregnancy.

Ewes carrying twins or triplets are especially at risk, as are animals in very poor or very fat condition. The underlying cause is usually underfeeding, or a sudden reduction in food intake, at a time when energy needs are rapidly increasing.

Risk Factors

• Multiple lambs

• Poor weather with inadequate shelter

• Sudden feed changes or disruptions

• Poor body condition (too thin or too fat)

Signs of Sleepy Sickness

• Sluggishness or general lethargy

• Loss of appetite

• Staggering or aimless walking

• Twitching of the ears and face

• Blindness

• Lying down with the head held up

• Coma and death, usually within 2 to 7 days

The onset is usually gradual, unlike other metabolic diseases such as milk fever.

Diagnosis

Animals affected by acetonaemia excrete ketones in their breath and urine. Ketones have a sweet chemical smell, like nail polish remover, which about half of people can detect.

A vet can measure blood ketone levels to detect problems early, often before clinical signs appear.

Prevention

Prevention depends on consistent and adequate feeding. Cows and ewes should receive increasing levels of energy-dense feed in the weeks before calving or lambing. In many cases, pasture alone is not enough.

Tips include:

• Monitoring body condition

• Supplementing with grain or concentrates where needed

• Providing shelter during poor weather

• Avoiding sudden feed changes in late pregnancy

Treatment

Treatment is difficult once signs are obvious, particularly if the animal has been underfed for some time. In these cases, liver damage may already be present.

Oral energy supplements (sometimes with added electrolytes) can help, but only if given early. Always contact your vet as soon as signs appear.

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